Paranormal Activity creator Oren Peli’s latest horror outing follows a group of tourists trapped in an abandoned city near the site of the Chernobyl nuclear disaster, and despite rumors before the first trailer was released, the film is decidedly not found footage. EW chatted with Peli and co-producer Brian Witten about what we can expect from their newest chillfest (released May 25), how they kept the plot secret, and what scares them.

ENTERTAINMENT WEEKLY: Where did the idea for the movie come from? Who conceived it?

OREN PELI: It started originally with me just goofing around on the Internet. I’ve known about the Chernobyl disaster, but I didn’t realize that there was an abandoned city called Prypiat right next to it. So I started browsing on the Internet and I found that people would go there on tours and take pictures and videos. I just thought it was amazing that such a place exists, basically an abandoned ghost town that’s modern. We’re not talking about a town that’s been abandoned from the Wild West era. It wasn’t even abandoned in the regular sense of the word that people just picked up their things and left. It’s like, people vanished. They didn’t even have time to take their belongings, so it’s kind of frozen in time, and I was just extremely fascinated by it and because it’s so eerie, I thought it would make a great setting for a horror movie.

A lot of people thought this was going to be a found footage film. Was it tossed around as a possibility?

PELI: We entertained it in the beginning but the theory just doesn’t make sense, considering where the story was going, that the characters would keep filming. So there are maybe three minutes or so in the movie, I would say, that are self-filmed on a video camera or cell phone.

How do you think you’ve influenced found footage movies of recent years?

PELI: Well, I don’t think I really invented it. I followed the footsteps of The Blair Witch Project, which was really the first commercially successful found footage film, and Paranormal Activity followed the formula. I do like found footage films, and I think the sense of realism in them can make a horror movie much scarier in some cases. But I think it’s on a case-by-case basis. Sometimes it makes sense for a movie and a movie can be great in the found footage format, and other times that movie can work better in a different format. In the case of Chernobyl Diaries, we did want to retain a lot of the positive things that you sometimes get in found footage films, like the realistic acting and the honest portrayal of events, so to speak, so it doesn’t feel too slick. It feels real without having to be found footage.

Tell me a little about how you picked this group of cast members.

PELI: We went into it knowing that the movie would live or die based on the quality of the acting, and we took it very seriously. We actually had a very similar auditioning process to what I’ve used in the past. It was all improvised, and the actors didn’t know what the movie was going to be about.

BRIAN WITTEN: We made fake scenes. We came up with different things and said, “Imagine you’re trapped in a train, there’s an earthquake, the train derails, you’re now underground. Some people are dead, you’re trapped, you don’t know if you’re going to get out and you’re there with your girlfriend.” And we would begin the scene. So when we auditioned [actors], we didn’t give out scripts or treatments.

PELI: We threw them right into the pool and let them improvise. We wanted to make sure that they’re not just taking turns reading lines. They’re real people, experiencing the moment.

How hard is it in general with the Internet to keep details about your movie under wraps?

PELI: I’m experiencing that every year with Paranormal Activity, when people are trying to gather information about what’s happening in the next movie. The best thing is to just work with a small group of people whom you trust and just know when to keep your mouth shut and not talk to too many people, and when you do, we were fanatical about not sharing the script with anyone that didn’t need to have it. And we used a fake name for the project.

What was the name?

PELI:The Diary of Lawson Oxford, which had absolutely nothing to do with Chernobyl.

How might Chernobyl Diaries be similar or different to the Paranormal Activity series?

PELI: Although it’s not a found footage movie, it does have a very different style where we worked really hard to give it a feel like you’re there with them, going along with our group on the tour. There are little things that we did that would be very untraditional in the way modern films are made. For example, once we get into the van to ride into the city, we stay inside the van with our group the entire time. There are no exterior shots or establishing shots. You definitely get the feeling that you’re riding with them, and the natural acting of the cast helps to create the sense that what you’re watching feels very real. There’s a lot of improvisation, a lot of cross talk, so in a way it doesn’t feel like a polished movie. It feels very raw.

After working in horror movies for so long, do you still get scared?

WITTEN: Totally. Before we started shooting, I came home one night and it was pitch black and my alarm said “back door alarm alert” or something. I immediately called 911 and walked through my house, but there was nothing there. In my mind, because of horror, I thought, “Well, what if the person’s upstairs hiding in a closet? And he or she is waiting for me to go upstairs and that’s part of their master plan?” I don’t think a normal person would go, “Wait a minute! The killer might be hiding upstairs and that’s part of the plot. They’re gonna wait for me to go upstairs to my bedroom and then get me.”